Drill-grinding mechanism



Dec. 29, 1936. c. E. YOUNG I DRILL GRINDING MECHANISM Filed Feb. 2'7, 1952 2 Sheets-Sheet l -fiwnlbr: M

Q4 ZMYQ JM Dec. 29, 193

C. E. YOUNG DRILL GRINDING MECHANISM FiledF e b. 27, 1952 2 she ets sheet 2 VIII/Iv Inventor g;

Q21 Afl-oyne 4 Ar/I/l /////////////////4 Cir Patented Dec. 29, 1936 UNITED STATES PATENT OFFICE 13 Claims.

My invention relates to drill grinding mechanisms, and more particularly to a fixture for holding the drill in the proper relation to the face of the grinding wheel to give the desired angle and clearance.

The principal object of my invention is to provide a drill holder of the type arranged to oscillate in front of the grinding wheel and simultaneously turn the drill, the holder being supported in a novel form of swivel bearing which by a simple manual adjustment provides for oscillation of the holder on an axis parallel to the face of the grinding wheel, or on another axis at an acute angle to said face, whereby to enable grinding drills with little or no clearance, suitable for drilling soft metal, or grinding drills with greater clearance at the center, suitable for other purposes.

Another object consists in the provision of a screw-threaded adjustment on the holder for adjusting the point of the drill to obtain a desired clearance angle back of the cutting edge, while still always assuring the desirable straight cutting edge. 7

I attain these and other objects by the improved mechanism shown in the accompanying drawings, in which- Figure l is a side elevation of the mechanism, showing a drill in the holder with the point in contact with the grinding wheel; Figure 2 is a section on the line B-B of Fig. 1, looking in the direction of the arrows, showing the offset mechanism for clearance angle adjustment; Figure 3 is a section on the line AA of Fig. '1, looking in the direction of the arrows; Figure 4 is a plan view of the universal support for the rocker-stud sleeve, and Figs. 5 and 6 are diagrammatic views similar to a portion of Fig. 1, to better illustrate the operation of the adjustable swivel bearing.

The same reference numerals refer to corresponding parts throughout the views.

I is the grinding wheel of the drill grinder. 36 is a stud which projects from and is suitably secured in the frame 44 of the machine, and on which the mechanism of my invention is mounted. Said mechanism is carried on a mounting bracket 31 which is adjustably positioned on said stud 36. The forked bracket 35 is supported by the shouldered screw 34 which threads into the stud 33. Adjustment of the mounting bracket 31 is made by turning the knob 33 of the screw 32, which threads into the mounting bracket. Said screw 32 is provided with a shoulder or collar 32A which, with the knob 33, cooperates with the forked end of the bracket 35 to move the bracket 31 on the stud 36. Bracket 31 is clamped by its split bearing in any desired position of adjustment on stud 36 by turning the screw 4! by means of the handle 4 IA.

The upper end of the mounting bracket 31, as shown in Fig. 1, carries a bearing 31A. The axis CC of the hole in this bearing is parallel to the grinding surface of said wheel, as indicated in Fig. 5. In this bearing is journaled a bushing 40. The axis FF of the hole through bushing 40 is not parallel to the axis of the hole in 31A but at an acute angle thereto, as best appears in Fig. 6. The shoulder of the bushing 40 bears on the face of 31A and is normal to the hole in 31A, while the upper face of bushing 40 is normal to the hole through itself. With this construction, it is evident that one may swing the bracket on axis CC as in Fig. 5, or on axis FF, as in Fig. 6. The change in swivel axis from C-C to FF results in a. shift of the drill axis from EE to G-G, as clearly appears in Fig. 6.

The pivot stem or journal 23A of the swivel bracket 23 is journaled in bushing 40. A shoulder is formed at the point where the pivot 23A joins the body of the bracket 23, and this shoulder bears on the upper face of the bushing 40. There are two lugs 43 carried on the shoulder of said bracket 23 which are properly positioned to cooperate with the projection 31B of bracket 31 and limit the swinging movement of bracket 23. The other end of swivel bracket 23 is formed with a. curved surface on top and bottom, as shown in Fig. 3, the same being struck on arcs with a common center. This center therefore, concides with the axis of oscillation of the cradle 22, which is conformed on the bottom thereof to fit the curvature of the top of the bracket 23. This axis of cradle oscillation, as will soon appear, always coincides with the axis of any drill being ground.

The cradle 22 is held in place on bracket 23 by the rod 26 which is secured in the cradle, passes through a slot in the bracket 23, and is threaded into the fork-nut 28 and clamped bythe lock-nut 21. A sliding shoe 24 bears against the curved bottom surface of the bracket 23 and is held in place by the spring 25.

The rocker-stud 30 is pivoted in the fork-nut 28 by the pin 29 and extends downwardly through the sleeve 3!. The sleeve is supported by pivot- .screws 3IA (Fig. 4) which are threaded through the ring 3 IB. The ring 3|B is likewisesupported by similar pivot screws 31A which are threaded through the ring forming the lower end of the bracket 31.

l I is the drill holder which is supported at an angle with relation to the axis of the bearing 31A, equal to the lip angle of the drill [2 with relation to the axis of said drill, and parallel to the axis of oscillation of the cradle 22. The holder is a V-shaped trough supported on the cradle by the elevating screws 2. At the rear end of the holder, the screw has a thrust collar 2A and is threaded right hand, into a tapped lug on the holder, while the front screw turns freely in lug 42 on the cradle 22 and is threaded left hand through a bracket 3 on drill holder II. This mechanism is provided to make possible the placing of the axis of drills of various diameters, in coincidence or in the same plane with the axis of cradle osci1 lation.

Referring to Fig. 1, a cap l9, which is held to the bracket 3 by machine screws, retains bracket 3 in sliding engagement with the guide 20. Lug 42 is integral with the cradle 22 and is perforated for the elevating screw 2 and serves as a pointer to cooperate with graduations 313 on the side of the bracket 3 to indicate settings for different sizes of drills. Mitre gears I8 are secured to the screws 2 and cooperate with similar gears I! which are secured to shaft 2|. Shaft 2| is journaled in suitable bearings in the cradle 22 and is provided with a hand-wheel I.

A lug l5, depending from the holder ll, cooperates with bracket 3 to form a slide for lateral adjustment of the front end of holder II, to obtain different clearance angles on the drill back of the cutting edge. A lug 3A (Fig. 2) projects from the back of the bracket 3 and is perforated for the clearance adjusting screw I 6. Another lug IIA depends from the holder II in line with the lug 3A. Lug HA is threaded to cooperate with screw 16. Adjusting screw I6 is journaled in lug 3A and is shouldered against the face of it, while a collar ISA bears against the back of said lug. Graduations on bracket 3 and on lug l5 indicate the extent of offset adjustment for clearance.

In Fig. 2 the drill is shown offset to the right of the center line C-C. Adjustment of the screw l6 would move the drill laterally, toward the left, until its axis would lie on the aforesaid center line. The axis of said drill would then coincide with the axis of oscillation of the cradle, previously mentioned. The position of the drill would then be indicated by the graduations 30 as zero offset and the other graduations to the right, would indicate the amount of possible lateral offset.

The tail-stock 5 is a V-shaped block which is perforated for the tail-stock spindle 4. A clamp 8 is fastened to the tail-stock by a machine screw 1. Clamp 8 has outwardly extending fingers which engage the outside of the holder II. The spindle 4 is secured in the spindle head 10 and is threaded through a nut 6. I3 is the lip-rest and is fastened to the front end of the holder l I.

The mode of operation is as follows: A drill l2, isplaced in the holder with a lip of the drill stopped against the lip-rest. The hand-wheel l, is turned to operate the elevating screws to adjust the holder to the position where the center or axis of the'drill will coincide with the axis of oscillation of the cradle. The graduations 3B should indicate the drill size at this setting. The

thereby feed the drill into the grinding wheel l4. Adjustment for clearance is then made by turning the screw l6, which moves the front end of the holder l l laterally with relation to the cradle 22 an amount indicated by the graduations 3C. This lateral adjustment will move the axis of the drill away from the axis of oscillation of the cradle and the point of the drill will then describe an arc of a circle, with the axis of oscillation as a center, as the cradle is oscillated. Or-

dinarily, it probably would not be the practice to first make the axis of the drill coincide with the axis of oscillation of the cradle and then offset for clearance as described, with each drill to be ground. The graduations 3B and 30 make such action unnecessary as they indicate at once the correct adjustment. The above description, specifying that the drill axis is first made coincident with the axis of oscillation of the cradle and afterward moved laterally from said axis of oscillation, is intended to give a clear understanding of the theory involved in properly locating the drill for grinding.

The bushing 40, when screw 39 is tightened and the screw 38 loosened, will turn with stem 23A on the axis CC, parallel to the face of the wheel l4. See Fig. 5. This will result in the drill being ground with little or no clearance, such as will be suitable for drilling lead or other soft metal, where there is little or no clearance required. However, let us assume that screw 39 is loosened and screw 38 is tightened: This clamps the bushing 40 to the bearing 31A and permits the stem or journal 23a of the swivel-bracket 23 to turn in the bushing 40 on axis F--F, at an acute angle relative to the face of the wheel 14, as shown in Fig. 6. This results in a drill being ground with greater clearance, suitable for other purposes.

In grinding a drill, the mechanism is swung to the right until the stop 43 contacts with stop 3TB. As the mechanism is moved, the rockerstud 30, cooperating with the sleeve 3|, swings the cradle 22 through an arc and thereby rotates the drill sufficiently to fully grind the lip' The pivot 29, and the universal mounting for the sleeve 3|, permits this oscillation with any adjustment.

It is believed the foregoing description conveys a good understanding of my invention. The appended claims have been drawn with a view to covering all legitimate modifications and adaptations.

I claim:

1. In mechanism of the character described, the combination with a frame and a grinding wheel providing a fiat grinding face in a substantially vertical plane, of a bracket disposed at an acute angle with respect to the face of said wheel and pivotally supported on said frame on a substantially vertical axis for oscillation relative to said wheel, said bracket having an arcuate seat provided thereon struck on a transverse arc whose center is above the bracket and coincident with the axis of a drill to be ground, a cradle slidably seated on said bracket for rocking movement transversely with respect thereto, a V-shaped drill holder adjustably supported on the cradle and extending therefrom toward the face of the wheel, screw threaded means for ad justing the holder toward or away from the cradle, whereby to center a drill therein on the aforesaid drill axis irrespective of the drill diameter, connections between the cradle and the frame whereby the cradle is rocked by the 0501].

lation of the bracket relative to the frame, and other screw threaded means for adjusting the drill holder transversely relative to the cradle.

2. In mechanism of the character described, the combination with a frame and a grinding wheel providing a flat grinding face in a substantially vertical plane, of a bracket disposed at an acute angle with respect to the face of said wheel and pivotally supported on said frame on a substantially vertical axis for oscillation 'relative to said wheel, said bracket having an arcuate seat provided thereon struck on a transverse arc whose center is above the bracket and coincident with the axis of a drill to be ground, a cradle slidably seated on said bracket for rock ing movement transversely with respect thereto, a V-s'haped drill holder adjustably supported on the cradle and extending therefrom toward the face of the wheel, screw threaded means for adjusting the holder toward or away from the cradle, whereby to center a drill therein on the aforesaid drill axis irrespective of the drill diameter, connections between the cradle and the frame whereby the cradle is rocked by the oscillation of the bracket relative to the frame, the pivotal support for said bracket on said frame comprising a fixed bearing whose axis is substantially parallel with the face of the grinding wheel, a bushing therein having a. bore whose axis is at an acute angle to the aforesaid axis, a journal on said bracket entered in said bore, and means for releasably and selectively securing the bushing to the hearing or the journal.

3. In mechanism of the character described, the combination of a frame, an oscillating support pivoted on the frame on a substantially vertical axis and inclined at an acute angle with respect to said axis, a cradle slidably seated on said support for transverse rocking movement about a drill axis, a V-shaped drill holder adjustably mounted on said cradle, screw threaded means for adjusting said holder toward or away from the cradle whereby to center a drill therein on the aforesaid drill axis, connections between the cradle and the frame whereby the cradle is rocked by the oscillation of the support, and other screw threaded means for adjusting the drill holder transversely relative to the cradle.

4. In mechanism of the character described, the combination of a frame, an oscillating support pivoted on the frame on a substantially vertical axis and inclined at an acute angle with respect to said axis, a cradle slidably seated on said support for transverse rocking movement about a drill axis, a V-shaped drill holder adjustably mounted on said cradle, screw threaded means for adjusting said holder toward or away from the cradle whereby to center a drill therein on the aforesaid drill axis, connections between the cradle and the frame whereby the cradle is rocked by the oscillation of the support, the pivotal support for said oscillating support on said frame comprising a fixed bearing whose axis is substantially vertical, a bushing therein having a bore whose axis is at an acute angle to the aforesaid axis, and a journal on said support entered in said bore, and means for releasably and selectively securing the bushing to the bearing or the journal.

5. In mechanism of the character described, the combination of a frame, an oscillating support pivoted on said frame on a substantially vertical axis and inclined at an acute angle with respect to said axis, a cradle slidably mounted on said support for oscillation transversely with respect thereto about a drill axis, connections between the cradle and the frame whereby the cradle is rocked by the oscillation of the support, a 'V-shaped drill holder arranged to be supported on the cradle, two screws disposed at right angles to the cradle and holder, one at the rear end of said holder and the other intermediate the ends thereof for adjusting the holder toward or away from the cradle whereby to center a drill therein on the aforesaid drill axis, said holder being pivoted on the first-mentioned screw for lateral movement relative to the cradle, and screw threaded means for swinging said holder laterally with respect to said cradle.

6. Mechanism as set forth in claim 5, wherein the pivotal support for said oscillating support on said frame comprises a fixed bearing whose axis is substantially vertical, a bushing therein having a bore whose axis is at an acute angle to the aforesaid axis, and a journal on said support entered in said bore, the mechanism including means for releasably and selectively securing the bushing to the bearing-or-the journal.

"I. In mechanism of the character described, the combination of a frame, an oscillating support pivoted on the frame on a substantially vertical axis and inclined at an acute angle with respect to said axis, a cradle slidably seated on said support for transverse rocking movement about a drillaxis, a drillholder adjustably mounted on said cradle, screw threaded means for adjusting said holder toward or away from the cradle whereby to center a drill therein on the aforesaid drill axis, a block slidable transversely on the nether side of said support with the cradle, spring means resiliently urging the block and cradle toward each other, and connections between the cradle and the frame whereby the cradle is rocked by the oscillation of the support.

8. In a drill-grinding mechanism, the combination of a frame, a grinding wheel providing a flat grinding face in a substantially vertical plane with respect thereto, a bracket disposed at an acute angle with respect to the face of said wheel and having a journal disposed normally substantially parallel with the fiat grinding face to support the bracket on the frame for oscillation laterally in front of the grinding face, a drill holder on said bracket, and an adjustable bearing on the frame receiving said journal, said bearing being constructed to permit movement of the journal from substantial parallelism to the grinding face to acute angle relationship with respect thereto, for the purpose described.

9. In a, drill-grinding mechanism, the combination of a frame, a grinding wheel providing a flat grinding face in a substantially vertical plane with respect thereto, a bracket disposed at an acute angle with respect to the face of said wheel and having a journal disposed normally substantially parallel with the flat grinding face to support the bracket on the frame for oscillation laterally in front of the grinding face, a drill holder mounted on said bracket and pivoted with respect thereto at that end remote with respect to the grinding face for movement in a plane parallel to the plane of the bracket, and screw threaded means for moving said holder on said pivot with respect to the bracket.

10. In a drill-grinding mechanism, the combination of a frame, a grinding wheel providing a flat grinding face in a substantially vertical plane with respect thereto, a bracket disposed at an acute angle with respect to the face of said wheel and having a journal disposed normally substantially parallel with the flat grinding face to support the bracket on the frame for oscillation laterally in front ofthe grinding face, a drill holder mounted on said bracket and pivoted with respect thereto at that end remote with respect to the grinding face for adjustment in a plane parallel to the plane of the bracket, screw threaded means for so adjusting said holder with respect to the bracket, and an adjustable bearing on the frame receiving the aforesaid journal, said bearing being constructed to permit adjustment so as to change the position of the journal from substantial parallelism to the grinding face to acute angle relationship with respect thereto, for the purpose described.

11. In a drill-grinding mechanism, the combination with a frame and algrinding wheel providing a flat grinding face in a substantially vertical plane, of a bracket disposed at an acute angle with respect to the face of said wheel and pivotally supported on said frame on a substantially vertical axis for oscillation relative to said WheeLa cradle slidably mounted on said bracket for oscillation transversely with respect thereto about a drill axis, means for rocking the cradle relative to the bracket in the oscillation of the bracket, a drill holder carried on the cradle and extending toward the face of the grinding wheel, a pivot at one end of the holder permitting lateral swinging movement of the holder relative to the cradle, and screw-threaded means at the other end of the holder for swingably adjusting said holder laterally with respect to said cradle.

12. In mechanism of the character described, the combination of a frame, an oscillating support pivoted on said frame on a substantially vertical axis and inclined at an acute angle with respect to said axis, a cradle slidably mounted on said support for oscillation transversely with respect thereto about a drill axis, means for rocking the cradle relative to the oscillating support in the oscillation of said support, a drill holder arranged to be supported on the cradle, two screws disposed at right angles to the cradle and holder, one at the rear end of the holder and the other intermediate the end thereof for adjusting the holder toward or away from the cradle whereby to center a drill therein on the aforesaid drill axis, said holder being pivoted on one of said. screws for lateral movement relative to the cradle, and screw-threaded means for swingably adjusting the holder laterally with respect to said cradle.

13. Mechanism as set forth in claim 12 including a means interconnecting the two screws for simultaneous operation whereby to maintain the drill holder in parallelism with the cradle in different adjustments thereof.

CLAYTON E. YOUNG. 

